説明
Precision is a relationship between two surfaces. A rotary table is the simplest way to add a fourth axis to a three-axis mill, and it is also the accessory where cheap examples reveal themselves fastest. Backlash, a scale that drifts, a chuck that will not repeat, and suddenly the curved slot that looked fine on the drawing is two thousandths out at the far end.
This 4 inch unit is built for small mills and the work they actually get: dividing cuts, bolt circles, radius slots, angled faces and light production runs. The table is 100mm in diameter with an 80mm three-jaw chuck, mounted either horizontally or vertically, sitting 120mm high in the horizontal position and 86mm centre height when vertical. Those numbers decide whether your spindle can reach the work, so they are worth checking against your machine before ordering.
The worm gear runs at 1:36, which means one full turn of the handwheel moves the table ten degrees. The handwheel scale divides into 100 graduations with a 6 minute value per division, and a dedicated degree lock holds the setting once it is made. That combination is what makes dividing work practical: you set an angle, lock it, cut, release and index. The vernier reading is deliberately simple, since a scale you have to interpret is a scale that introduces error.
The chuck arrives with both internal and external jaws, opened and closed with a T-shaped wrench, and it holds round, hexagonal and square stock without a separate collet set. Net weight is 5.3kg, which is heavy enough to stay rigid under a cut and light enough for one person to lift onto a bench mill. For a hobby machinist moving from clamped work to indexed work, this is the accessory that changes what the machine can make.
Ten degrees per turn, six minutes per line, and no guessing at the angle.
What the Index Head Actually Does
- ✦ 4 inch / 100mm table with an 80mm three-jaw chuck for round, hex and square stock.
- ✦ Horizontal or vertical mounting at 120mm top height or 86mm centre height to suit your spindle reach.
- ✦ 1:36 worm gear ratio giving ten degrees of table rotation per full handwheel turn.
- ✦ 100-division handwheel scale at 6 minutes per graduation for accurate indexing.
- ✦ Dedicated degree lock that holds the setting through a cut instead of drifting under load.
- ✦ Internal and external jaws supplied with a T-shaped chuck wrench, no collet set required.
- ✦ 5.3kg cast body rigid under load and light enough for a bench mill setup.
Technical Specifications
- Table diameter: 4 in / 100 mm
- Chuck: 3-jaw, 80 mm, internal and external jaws included
- Worm gear ratio: 1:36
- Handwheel scale: 100 graduations, 6 minutes per division
- Top height, horizontal: 4.7 in / 120 mm
- Centre height, vertical: 3.4 in / 86 mm
- Overall dimensions: 6.3 x 5.8 x 4.7 in / 160 x 148 x 120 mm
- Net weight: 11.7 lbs / 5.3 kg
- Mounting: horizontal or vertical
- Certification: CE
Where It Belongs
Bench mill owners use the 4 inch table for bolt circles on flange plates, radius slots in brackets and angled faces on small housings that would otherwise need a tilting vise and a lot of patience. Model engineers value the 1:36 ratio because dividing head work becomes arithmetic rather than guesswork. Small job shops keep one mounted on a dedicated plate so a dividing job can be set up without disturbing the main vise. Gunsmiths and knife makers use the indexing capability for fluting and radial features on round stock. Anyone producing a short run of identical parts benefits more from repeatable indexing than from a larger machine.
Questions Buyers Ask Before Ordering
Q: Will this fit my mill?
A: Check two numbers against your machine: the 120mm horizontal top height, which sets how much Z travel the setup consumes, and the 100mm table diameter, which sets the work envelope. A bench mill with limited quill travel may need the table mounted vertically or on a riser block.
Q: How do I calculate a division on a 1:36 table?
A: One handwheel turn equals ten degrees. For a 24-hole bolt circle, each step is 15 degrees, so one turn plus half of the 100-division scale at 6 minutes per division. For 36 divisions, one turn per step lands exactly, which is why this ratio is popular for dividing work.
Q: Does the chuck hold square stock?
A: The three-jaw chuck grips round and hexagonal stock accurately and square stock with reasonable centring. For critical square work, indicate the part after clamping or use the four-jaw chuck from your lathe on a backplate.
Q: Is there backlash in the worm gear?
A: Any worm drive has some, and this table is no exception. The practical approach is to always approach the final position from the same direction, which removes the effect from the work. A degree lock holds the setting once it is made.
Q: Can I mount it vertically on the mill table?
A: Yes, the body is machined for both orientations, with the vertical centre height at 86mm. Vertical mounting is how you cut angled faces or drill radial holes, and it needs the table bolted to an angle plate or directly to a slotted table.
Q: Is the chuck removable?
A: Yes, it mounts on a backplate and comes off for cleaning or for fitting a different workholding fixture. Removal is worth doing after any job that produces fine chips, since swarf inside the chuck is the usual cause of runout that appears months later.
Customer Reviews
Payment and Security
お支払い情報は安全に処理されます。 クレジットカードの詳細を保存したり、クレジットカード情報にアクセスすることはありません